Covers and ducts for machinery

ABSTRACT

The specification describes adapted to provide machinery covers and parts thereof including engine covers for internal combustion engines in vehicles and aeroplanes. The members are constructed in two parts with a resilient material interposed to minimize vibration and vibratory noise caused by operation of the machinery.

United States Patent Vickers et a]. [4 1 Sept. 19, 1972 [54] COVERS ANDDUCTS FOR 3,114,568 12/1963 Buono ..2 85/235 MACHINERY 2,364,234 12/1944Morell ..220/67 X 72 Inventors: olm ck 64 C] l d A 2,835,360 5/1958Bernardoni et al ..52/403 1 j an 3 $132,, i l 3,351,594 12/1967 010811@1111. ..220/80 Darling, England FOREIGN PATENTS R APPLICATIONS [22]1968 536,846 /1941 Great Britain ..285/53 21 Appl. No.: 726,421

Primary Examiner-David J. Williamowsky in" Assistant Examiner-Wayne L.Shedd Ford Priority Attorney-Jones and Lockwood May 4, 1967 GreatBritain ..20,826/67 [57] ABSTRACT [52] 11.8. C1. ..285/49, 285/235,285/238,

' 220/80, 52/403 The specification describes adapted to provlde 5111111. c1. ..Fl61 55/02 machinery covers and Parts thereof includingengine 53 dd of s 235 49 174 235 417 371 covers for internal combustionengines in vehicles and 1 2 69, 398, 238, 47, 53, 59, 391, 392,aeroplanes. The members are constructed in two parts 330, 331, DIG. 9;52/393, 395, 400, 403; with-a resilient material interposed to minimizevibra- 220/5, 67, 75, tion and vibratory noise caused by operation ofthe machinery. [56] References Cited 4 Chin's 2 Drawing g UNITED STATESPATENTS 2,776,151 l/1957 Harkenrider ..285/238 X PATENTED SEP 19 I972COVERS AND DUCTS FOR MACHINERY This invention relates to members adaptedto provide machinery covers and parts thereof.

It is an object of this invention to provide such members which have avibration damping effect and thus minimize vibration where it isunwanted, and also reduce noises such as drumming and resonancy causedby vibration.

According to this invention we-provide a member adapted to form amachinery cover or part thereof divided at a zone'spaced from means forattachment'of the member to the machinery, the divided components beingseparated by a narrow gap and connected together by a band of aresilient naturalor synthetic plastics material which fills the said gapand overlaps and is bonded to the marginal surfaces of the components oneither side of the gap. In one form of the invention the plasticsmaterial overlaps and is bonded to the marginals urfaces both inside andoutside the'com ponents; a

At least one of the components is provided-with at least one keyingaperture extending therethrough and the resilient material extends tofill the said keying apertures.

Y The member may be in the form of an engine cover having a flange orrim for attachment to the engine. Such an engine cover may be a valvecover, rocker box cover, crank case access cover or sump. Such membersmay be used in internal combustion engines, particularly diesel engines,air-compressors and the like and may be usedin two and four-wheeledvehicles and airplanes.

With the aid of suitable plastics material and a suitabl e bondingtechnique, the invention is applicable to such members of variousferrous and non-ferrous metals, such ,as mild steel, stainless steel andferrous alloys, aluminum, magnesium, zinc, brass and other copperalloys.

When the member is made by pressing from sheet metal, or by castingmethods other than die casting it may be preferable to carry out themethod by cutting a completely preformed member along or around theaforesaid dividing zone so asto remove enough metal to create therequired gap. Alternatively, with the aid of a sufficiently accuratemethod, such as die-casting, thecomponents of the member may beseparately preformed to eliminate the step of cutting to provide thedivision.

Suitable plastics materials, for use with cast aluminum or magnesiumalloymembers, as commonly employed for example for engine covers, arenitrile rubbers and neoprene rubbers.

An embodiment of the invention will be briefly described, by way ofexample, with reference to the accompanying drawings, wherein:

FIG. 1 is a fragmentary section of a cast aluminum rocker box cover, onthe line 1-1 of FIG. 2, which is a fragmentary elevation of the same inthe direction of arrow II.

Referring to FIGS. 1 and 2 the rocker box 1 of which a portion is shownin the drawings is a deeply dished structure of substantiallyrectangular form having a surrounding rim 2 by which it may be clamped,with the interposition of a gasket, upon an internal combustion engineto cover the valve-operating rocker mechanism. The rocker box as shownis divided into two components 3 and 4, the component 3 being integralwith the flange 2, and the component 4 comprising the top of the box andadjacent portions of the walls thereof. The side wall portions 5, 6respectively of the components 3 and 4 are aligned as indicated in FIG.1 and divided by a gap 7 which extends completely around the box and isparallel to the engaging surface 8 of the flange 2. The two components 3and 4 are secured together by a band 9 of a resilient plastics material,preferably a nitrile or neoprene rubber, which is moulded or expanded onto marginal portions of the walls 4 and 5 adjacent the gap 7, while thetwo components are held in a suitable jig.

The jig referred to in the last paragraph provides mould surfaces whichhave an internal surface correspondingto the outer surface of thefinished band 9. In the expansion process, the strips of rubber are heldin position with the components on the jig and the as sembly submittedto heating and/or steam treatment to cause the rubber to expand to thedesired dimension. to fill the joint.

In order more efiectively to secure the components 3 I and 4 togetherwith the aid of the rubber band 9, the

the holes 10 and 1 1 so as to supplement the bonding cffeet of therubber adhering to the inner and outer surfaces of the walls 5 and 6 ofthe components.

In this embodiment, a flexible joint is made in a peripheral wall of acover which is substantially perpendicular to the plane of the surface 8at which the cover is secured to an engine. However, a like mode may beemployed to form a cover which is substantially flat, -or has a slight,substantially flat or convex or concave, dishing. The effect of theresilient support provided for the middle part of the cover, which mayin many cases haveJa considerable area, is to reduce appreciably anydrumming or resonance of said cover part due to vibratory noise ofmechanism enclosed by the cover. I

Alternatively such a joint may be used to give a shock or vibrationdamping effect in such members as aero-engine sumps, motor cyclecarburetor suspensions and the like.

The use of such a joint gives a firm bond and yet can be used with metalof quite thin dimensions because of the overlap to the side of the gap.

What we claim and desire to secure by Letters Patent is:

1. A member adapted to form a machinery cover, or a part of such a coverdivided at a zone spaced from means for its attachment to the machineryto provide two components which are separated by mutual linear movementto form an intervening narrow gap with marginal portions of thecomponents at each side of the gap respectively, at least one of thecomponents being provided with one or more keying apertures extendingthrough the said marginal portion in a direction substantially at rightangles to the direction of said linear movement, the components beingconnected together and insulated from mutual vibration transmission by aband of resilient natural or synthetic plastics material which fills thegap and overlaps and is bonded to the marginal portion of the componentson either side of the gap and extends to fill the said keying apertureor apertures.

2. A member according to claim 1 wherein the plastics material is rubberwhich rubber has been expanded in size to fill the said gap.

3. A member according to claim 1 wherein the said components have aplurality of said keying apertures, the keying apertures on therespective components being in staggered relationship.

4. In machinery, a member forming a cover therefor,

means for attachment of the member to the machinery, a part of the coverdivided at a zone spaced from said attachment means and therebyproviding two components having inside and outside marginal surfaces,the divided components being separated by a narrow gap, and eachcomponent being provided with at least one keying aperture extendingtherethrough, the components being connected together by a band ofrubber which has been expanded in size to fill the said gap and keyingapertures and which band overlaps and is bonded to the marginal surfacesof the inside and outside of the components on either side of the gap.

* a: a m n-

1. A member adapted to form a machinery cover, or a part of such a coverdivided at a zone spaced from means for its attachment to the machineryto provide two components which are separated by mutual linear movementto form an intervening narrow gap with marginal portions of thecomponents at each side of the gap respectively, at least one of thecomponents being provided with one or more keying apertures extendingthrough the said marginal portion in a direction substantially at rightangles to the direction of said linear movement, the components beingconnected together and insulated from mutual vibration transmission by aband of resilient natural or synthetic plastics material which fills thegap and overlaps and is bonded to the marginal portion of the componentson either side of the gap and extends to fill the said keying apertureor apertures.
 2. A member according to claim 1 wherein the plasticsmaterial is rubber which rubber has been expanded in size to fill thesaid gap.
 3. A member according to claim 1 wherein the said componentshave a plurality of said keying apertures, the keying apertures on therespective coMponents being in staggered relationship.
 4. In machinery,a member forming a cover therefor, means for attachment of the member tothe machinery, a part of the cover divided at a zone spaced from saidattachment means and thereby providing two components having inside andoutside marginal surfaces, the divided components being separated by anarrow gap, and each component being provided with at least one keyingaperture extending therethrough, the components being connected togetherby a band of rubber which has been expanded in size to fill the said gapand keying apertures and which band overlaps and is bonded to themarginal surfaces of the inside and outside of the components on eitherside of the gap.